Archive for
July 31st, 2008

On August 1, 2008, a total solar eclipse will occur as the new moon moves directly between the sun and the earth. The moon’s umbral shadow will fall on parts of Canada, Greenland, the Arctic Ocean, Russia, Mongolia, and China. The Exploratorium’s eclipse expedition team (our fifth!) will Webcast the eclipse live from the remote Xinjiang Uygur Autonomous Region in northwestern China near the Mongolian border

Sorry for the late notice. Someday, technology will allow us to predict these more than a day in advance.

Mr. Vansevenant, who after Stage 18 sits in 150th place, some 3 hours and 45 minutes behind Mr. Sastre, is indeed the worst-placed rider in the Tour de France. But, in turn, he has outlasted those who abandoned the Tour through illness, injury or simple exhaustion; those who were eliminated for failing to finish within each day’s time limit and are forced to withdraw; and those who were banned or withdrew for doping-related causes. From year to year, about 20% of the riders drop out. In other words, you can’t simply coast to last place; you have to work for it.

Dealing with Uncertainty at Backreaction, in the context of “science is never 100% certain” and how this plays out with public perception.

There are times when this seems to be a no-win scenario: if you fail to address the uncertainty and have to make any changes to your conclusions, you lose credibility, but if you point out the uncertainty, someone will run with it, exaggerating it. One need go no further than discussions of global warming to see this in action.

One of my least favorite phrases in this area of discussion is “for all we know.” Statements that sound like “For all we know, the phenomenon could be caused by blargh” should be taken with a huge grain of salt, because one of the things science does is to widen the scope of what “all we know” entails, and correspondingly narrow the possible undiscovered explanations for the phenomenon. We rule things out, and attempt to do so in a quantifiable way — we limit the uncertainty. If you are doing an experiment and see something unusual in your data, you start systematically testing to see what could possibly be causing it. So if someone were to claim, “For all we know, that glitch is caused by a spurious magnetic field,” you can respond with “No, we tested the effect of a magnetic field, and eliminated that as a cause.” You do this all the time in setting up an experiment, and you continue to do it when running the experiment — doing everything you can to confirm that the correlation you see is actually causal. But I don’t think that this gets portrayed very well. There’s always someone out there trying to leverage science not being 100% certain, and instead portray uncertainty as being 0% certain, which is far from the truth.

Bee notes that

As I have previously said (eg in my post Fact or Fiction?) uncertainties are part of science. Especially if reports are about very recent research, uncertainties can be high.

And I recall that Feynman touches on this in Surely You’re Joking, Mr. Feynman!. Someone drew a conclusion based on the last data point in some experiment, and he realized that the last data point isn’t so trustworthy — if you weren’t pushing the limit of the apparatus, you’d have obtained more data, so this is certainly a valid point. And here one starts fighting the tendencies of the media, because if the result isn’t novel, it isn’t newsworthy. What ends up happening is that that the least reliable results, the ones most likely to be mistaken, are often the ones making the headlines. The study that challenges a long line of other research (which, being “as expected,” was ignored) gets notice, even though one expects, statistically, the occasional contradictory study. Such is the essence of random noise. This is made worse by the journalistic desire to show both sides of a story, even if there really aren’t two sides, as they have massively different amount of evidentiary support. This, too, misleads the general public about what is know, what is unknown and what level of confidence exists in science.

Our command picnic was Wednesday, and our volleyball team whipped the young whippersnapper summer interns to win the crown (something like 15-5 and 15-5, with traditional scoring). We had three of four people from the research group and one of the guys from the instrument shop to replace our missing player, and picked up a free-agent (and it turned out she was a ringer).

We won the tournament three years ago, carried by one very good player making up for the rest of us, following the strategy of just getting the ball over the net and letting the other team make the mistakes, and at this level of play, that was a pretty good strategy. That time we were aided by a quirk of the schedule that gave us a bye and our finals opponents (seabees) had to play three matches in a row. (we kept muttering “water’s for wimps!” in the short interlude before the final match, and kept reminding them that we were just a bunch of geeks) (We didn’t enter a team the last two years — our good player was injured and then absent, so we opted out)

This time the aid was having several good potential opposing players on vacation or opting for disc golf, and our free-agent addition having a nasty overhand serve that’s just too much for some of the players at the picnic level of play. There was some mumbling from one or two of our opponents about being on sand affecting their play. Sadly, my game is not noticeably impacted by the surface; I think I contributed more to scoring than to losing points. We showed that youth and enthusiasm is no match for age and treachery. Ha!